Please add support for programmatic exporting of Grids (SaveAsExcelFileAsync() and ExportToExcelAsync() ) with a GridExcelExportOptions argument and multi-column headers.

===

A potential workaround is to programmatically click the built-in export command button, which can even be hidden:

@using Telerik.Blazor.Components.Grid

@inject IJSRuntime JS

<PageTitle>Home</PageTitle>

<TelerikGrid Data="@GridData">
    <GridToolBarTemplate>
        <TelerikButton OnClick="@ExportGridWithOtherColumns">Export Programmatically</TelerikButton>
        <GridCommandButton Class="hidden-export-button" Command="ExcelExport">Export Natively</GridCommandButton>
    </GridToolBarTemplate>
    <GridSettings>
        <GridExcelExport OnBeforeExport="@OnGridBeforeExport" />
    </GridSettings>
    <GridColumns>
        <GridColumn Field="@nameof(Product.Id)" Width="100px" />
        <GridColumn Field="@nameof(Product.Name)" Width="120px" />
        <GridColumn Title="Product Details">
            <Columns>
                <GridColumn Field="@nameof(Product.Group)" Width="180px" />
                <GridColumn Field="@nameof(Product.Price)" DisplayFormat="{0:c2}" Width="120px" />
                <GridColumn Field="@nameof(Product.Quantity)" DisplayFormat="{0:n0}" Width="120px" />
                <GridColumn Field="@nameof(Product.Released)" DisplayFormat="{0:d}" Width="180px" />
                <GridColumn Field="@nameof(Product.Discontinued)" Width="100px" />
            </Columns>
        </GridColumn>
    </GridColumns>
</TelerikGrid>

<style>
    .hidden-export-button {
        display: none;
    }
</style>

<script suppress-error="BL9992">
    function clickExportCommandButton() {
        let hiddenExportButton = document.querySelector(".hidden-export-button");
        if (hiddenExportButton) {
            hiddenExportButton.click();
        }
    }
</script>

@code {
    private List<Product> GridData { get; set; } = new();

    private void OnGridBeforeExport(GridBeforeExcelExportEventArgs args)
    {
        List<string> exportableColumnFields = new List<string> { nameof(Product.Name), nameof(Product.Price), nameof(Product.Quantity) };
        List<GridExcelExportColumn> ColumnsToExport = new();

        foreach (GridExcelExportColumn column in args.Columns)
        {
            if (exportableColumnFields.Contains(column.Field))
            {
                ColumnsToExport.Add(column);
            }
        }

        args.Columns = ColumnsToExport;
    }

    private async Task ExportGridWithOtherColumns()
    {
        await JS.InvokeVoidAsync("clickExportCommandButton");
    }

    protected override void OnInitialized()
    {
        var rnd = Random.Shared;

        for (int i = 1; i <= 7; i++)
        {
            GridData.Add(new Product()
            {
                Id = i,
                Name = $"Name {i} {(char)rnd.Next(65, 91)}{(char)rnd.Next(65, 91)}",
                Group = $"Group {i % 3 + 1}",
                Price = rnd.Next(1, 100) * 1.23m,
                Quantity = rnd.Next(0, 10000),
                Released = DateTime.Today.AddDays(-rnd.Next(60, 1000)),
                Discontinued = i % 4 == 0
            });
        }
    }

    public class Product
    {
        public int Id { get; set; }
        public string Name { get; set; } = string.Empty;
        public string Group { get; set; } = string.Empty;
        public decimal Price { get; set; }
        public int Quantity { get; set; }
        public DateTime Released { get; set; }
        public bool Discontinued { get; set; }
    }
}

• If you select a row and then unselect that row (SelectedItems is empty), and hit the incorrectly enabled delete button, it removes a row that has not been selected. When there is no selected row, the delete tool should be disabled.

• If you use multiple selection, the delete tool will delete the last row, which is unexpected. It should delete all selected rows.

Workaround:

<TelerikGrid Data="@GridData"
             SelectionMode="@GridSelectionMode.Multiple"
             SelectedItems="@SelectedItems"
             SelectedItemsChanged="@( (IEnumerable<Employee> newSelected) => OnSelectedItemsChanged(newSelected) )"
             Height="300px">
    <GridToolBarTemplate>
        <TelerikButton Enabled="@(SelectedItems.Any())" OnClick="@DeleteSelectedEmployees">Delete</TelerikButton>
    </GridToolBarTemplate>
    <GridColumns>
        <GridCheckboxColumn SelectAll="true" />
        <GridColumn Field="Name" Title="Name" />
        <GridColumn Field="Team" Title="Team" />
    </GridColumns>
</TelerikGrid>

@code {
    private List<Employee> GridData { get; set; } = Enumerable.Range(1, 10).Select(i => new Employee
    {
        EmployeeId = i,
        Name = $"Employee {i}",
        Team = $"Team {i % 3}"
    }).ToList();

    private List<Employee> SelectedItems { get; set; } = new();

    private void OnSelectedItemsChanged(IEnumerable<Employee> items)
    {
        SelectedItems = items.ToList();
    }

    private void DeleteSelectedEmployees()
    {
        if (SelectedItems.Any())
        {
            GridData = GridData.Except(SelectedItems).ToList();
            SelectedItems.Clear();
        }
    }

    public class Employee
    {
        public int EmployeeId { get; set; }
        public string Name { get; set; }
        public string Team { get; set; }
        public override bool Equals(object obj) => obj is Employee e && e.EmployeeId == EmployeeId;
        public override int GetHashCode() => EmployeeId.GetHashCode();
    }
}

I'm using an OnRead grid with ExpandoObjects. The error happens on the backend when trying to process the result of ToDataSourceResult(...)

When trying to access the Items property of AggregateFunctionsGroup in a multi level grouping scenario, using ExpandoObject, and the top level group has a null key, trying to access the Items property will result in a NullReferenceException. I've made this helper, but it cannot process the subgroups because of this error.

private static void FlattenGroup<T>(AggregateFunctionsGroup group, List<T> result)
{
    if (group == null)
    {
        return;
    }

    if (group.HasSubgroups)
    {
        foreach (var sub in group.Items.OfType<AggregateFunctionsGroup>())
        {
            FlattenGroup(sub, result);
        }
    }
    else
    {
        result.AddRange(group.Items.OfType<T>());
    }
}

In a scenario where I have an ExpandoObject with properties A and B, where A = 1 and B = null; grouping by A then B works. Grouping by A or B alone also works. But grouping by B then A causes the NullReferenceException when trying to access the group.Items. 

When Virtual Scrolling is enabled and the grid is set to inline editing, clicking the Add button does not start editing on the first click. The button must be clicked twice for a new row to enter edit mode.

Steps to Reproduce:

1. Open this example - https://blazorrepl.telerik.com/QfaZEibY50abpby200

2. Scroll down the grid.

3. Click the "Add" button.

Upon the first click, a new row is inserted but then immediately closed. You have to click it a second time to insert a new row.

I want to change the default Grid loading animation to a pulsing loader indicator.

When enabling resizing and reordering for the Telerik Grid, using `MinResizableWidth` to set minimal column width will apply the constraint to the column position rather than the actual movable column. This means applying a min width of 200px to the first column will work as expected until the column is moved to another position. Now the column in question no longer has the min width applied, and the column that has moved into the first position has the 200px min width constraint. 

It appears this is due to the constraint being applied to the `data-col-index` rather than the `data-col-initialization-index`, or something to that effect.

The following example has a 200px min-width constraint applied to the "Name" first column, and no custom min-with applied to "Address" second column. Switching the columns by moving the "Name" after the "Address" will apply the constraint to the "Address" and not the "Name".

https://blazorrepl.telerik.com/QJEAcuPE41L7Uhiw44

Currently using 7.1.0 but looks to be an issue in later versions as shown by the REPL example. Tested in Firefox and Chrome.

The column position is arbitrary and the bug isn't due to the constraint being applied to the 0 column, applying the constrain to all even columns then shuffling would result in the constrain still being applied to all even columns.

If the GridScrollMode.Virtual is enabled for the Grid, and the NoDataTemplate exceeds the height of the Grid container, a user can infinitely scroll inside the table even when there is no data and the template is displaying.

===ADMIN EDIT===

A possible workaround is to apply "overflow-y: hidden;" when the NoDataTemplate is shown: REPL link.

Since verion 9, the new styling is doing something strange.

The issue is also observable on the Tererik demo site (as well as our published applications) but I have noticed its on webassembly more-so than server apps;

https://demos.telerik.com/blazor-ui/grid/adaptive

If I run the demo site, the new pagination style (where you can type the page you want to navigate to) will flash up for a second, then it will go back to the old style after a second or 2.

Would anyone know why this is happening?

The Grid performance worsens progressively with each subsequent edit operation. Please optimize that.

Test page: https://blazorrepl.telerik.com/mJuHFNbb17FpJu9b54

Click on a Price or Quantity cell to start edit mode and tab repetitively to observe the degradation.

Currently, when a user exports the Grid to Excel/CSV/PDF,  the export file is generated as a base64 string.

Please provide the file as a byte[] instead of a base64 string for better performance.

I have a Telerik Pager within a Telerik Grid. If I select a larger page size within the pager, then select a smaller size and do not scroll, the next time I open the pager, the dropdown portion opens in the wrong place. When I view the inspect tool, it appears that the CSS top value is not being updated when changing page sizes from bigger to smaller. Is this a Telerik limitation with the pager?
In the images, we select items per page from 10 to 25, and then we go immediately from 25 to 10 items per page. Without scrolling, we click into the drop down list again and we are able to replicate this issue.

Before: Items per page:     10 -> 25

After:    


Thank you in advance.

Consider the following scenario:

1. A user focuses a specific Grid cell through keyboard navigation.
2. The user tabs out of the Grid and then tabs back in.

In this case, the Grid should focus the last focused cell in step 1. Instead the Grid focuses the first header cell.

1. Go to https://demos.telerik.com/blazor-ui/grid/keyboard-navigation 
2. Click a data cell.
3. Click `Tab` or `Shift + Tab` to exit the Grid data area.
4. Click `Shift + Tab` or `Tab` to go back to the Grid data area.
5. Compare with https://www.telerik.com/kendo-angular-ui/components/grid/keyboard-navigation 

I have a Grid with row selection and column virtualization. After selecting all rows and zooming out my browser to 80% or less, the column virtualization stops working - data is not loaded in the cells on vertical scroll.

Reproduction REPL

The scenario is:

• Grid popup editing
• The model class has no parameterless constructor
• The Grid is using a popup <FormTemplate>

In this case, the Grid should not try to create or clone an edit item on its own. Instead, it should rely on the returned instance from OnModelInit. However, the Grid first fires OnModelInit and then it still tries to clone or create an edit item, which causes an exception.

A possible workaround is to manage the whole edit process manually, similar to the example with ListView popup editing.